import bigInt from "big-integer";

export const guid = () => {
  const Snowflake = /** @class */ (function() {
    function Snowflake(_workerId, _dataCenterId, _sequence) {
      // this.twepoch = 1288834974657;
      this.twepoch = 0;
      this.workerIdBits = 5;
      this.dataCenterIdBits = 5;
      this.maxWrokerId = -1 ^ (-1 << this.workerIdBits); // 值为：31
      this.maxDataCenterId = -1 ^ (-1 << this.dataCenterIdBits); // 值为：31
      this.sequenceBits = 12;
      this.workerIdShift = this.sequenceBits; // 值为：12
      this.dataCenterIdShift = this.sequenceBits + this.workerIdBits; // 值为：17
      this.timestampLeftShift = this.sequenceBits + this.workerIdBits + this.dataCenterIdBits; // 值为：22
      this.sequenceMask = -1 ^ (-1 << this.sequenceBits); // 值为：4095
      this.lastTimestamp = -1;
      //设置默认值,从环境变量取
      this.workerId = 1;
      this.dataCenterId = 1;
      this.sequence = 0;
      if (this.workerId > this.maxWrokerId || this.workerId < 0) {
        throw new Error(
            'config.worker_id must max than 0 and small than maxWrokerId-[' + this.maxWrokerId + ']'
        );
      }
      if (this.dataCenterId > this.maxDataCenterId || this.dataCenterId < 0) {
        throw new Error(
            'config.data_center_id must max than 0 and small than maxDataCenterId-[' +
            this.maxDataCenterId +
            ']'
        );
      }
      this.workerId = _workerId;
      this.dataCenterId = _dataCenterId;
      this.sequence = _sequence;
    }
    Snowflake.prototype.tilNextMillis = function(lastTimestamp) {
      var timestamp = this.timeGen();
      while (timestamp <= lastTimestamp) {
        timestamp = this.timeGen();
      }
      return timestamp;
    };
    Snowflake.prototype.timeGen = function() {
      //new Date().getTime() === Date.now()
      return Date.now();
    };
    Snowflake.prototype.nextId = function() {
      var timestamp = this.timeGen();
      if (timestamp < this.lastTimestamp) {
        throw new Error(
            'Clock moved backwards. Refusing to generate id for ' + (this.lastTimestamp - timestamp)
        );
      }
      if (this.lastTimestamp === timestamp) {
        this.sequence = (this.sequence + 1) & this.sequenceMask;
        if (this.sequence === 0) {
          timestamp = this.tilNextMillis(this.lastTimestamp);
        }
      } else {
        this.sequence = 0;
      }
      this.lastTimestamp = timestamp;
      var shiftNum =
          (this.dataCenterId << this.dataCenterIdShift) |
          (this.workerId << this.workerIdShift) |
          this.sequence; // dataCenterId:1,workerId:1,sequence:0  shiftNum:135168
      var nfirst = new bigInt(String(timestamp - this.twepoch), 10);
      nfirst = nfirst.shiftLeft(this.timestampLeftShift);
      var nnextId = nfirst.or(new bigInt(String(shiftNum), 10)).toString(10);
      return nnextId;
    };
    return Snowflake;
  })();

  return new Snowflake(1, 1, 0).nextId();
};